Lewis is referring to the following New Testament passages (all quoted from the King James Version).
Being born again: "Jesus answered and said unto him, Verily, verily, I say unto thee, Except a man be born again, he cannot see the kingdom of God" (John 3:3).
"Marvel not that I said unto thee, Ye must be born again" (John 3:7).
"Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently: Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever" (1 Peter 1:22-23).
Putting on Christ: "For ye are all the children of God by faith in Christ Jesus. For as many of you as have been baptized into Christ have put on Christ. There is neither Jew nor Greek, there is neither bond nor free, there is neither male nor female: for ye are all one in Christ Jesus" (Galatians 3:26-28).
Being formed in us: "My little children, of whom I travail in birth again until Christ be formed in you, I desire to be present with you now ..." (Galatians 4:19-20).
Have the mind of Christ: "For who hath known the mind of the Lord, that he may instruct him? But we have the mind of Christ" (1 Corinthians 2:16).